docs: def concat(self, other, inplace=False):
          '''Concatenate two ChemicalEntity of the same kind'''
          
          # Create new entity
          if inplace:
              obj = self
          else:
              obj = self.copy()
          
          # Stitch every attribute
          for name, attr in obj.__attributes__.items():
              attr.append(other.__attributes__[name])
              
          # Stitch every relation
          for name, rel in obj.__relations__.items():
              rel.append(other.__relations__[name])
          
          # Update maps
          
          # Update dimensions
          if obj.is_empty():
              obj.maps = {k: m.copy() for k, m in other.maps.items()}
              obj.dimensions = other.dimensions.copy()
          else:
              for (a, b), rel in obj.maps.items():
                  rel.append(other.maps[a, b])
              for d in obj.dimensions:
                  obj.dimensions[d] += other.dimensions[d]
          
          return obj